diff --git a/packages/flutter/lib/src/widgets/navigator.dart b/packages/flutter/lib/src/widgets/navigator.dart
index 65c199c13e4..e8f5700ab96 100644
--- a/packages/flutter/lib/src/widgets/navigator.dart
+++ b/packages/flutter/lib/src/widgets/navigator.dart
@@ -184,6 +184,9 @@ abstract class Route<T> extends _RoutePlaceholder {
   NavigatorState? get navigator => _navigator;
   NavigatorState? _navigator;
 
+  bool get _installed => _navigator != null;
+  bool _isInstalledIn(NavigatorState state) => _navigator == state;
+
   /// The settings for this route.
   ///
   /// See [RouteSettings] for details.
@@ -220,7 +223,7 @@ abstract class Route<T> extends _RoutePlaceholder {
   void _updateSettings(RouteSettings newSettings) {
     if (_settings != newSettings) {
       _settings = newSettings;
-      if (_navigator != null) {
+      if (_installed) {
         changedInternalState();
       }
     }
@@ -579,7 +582,7 @@ abstract class Route<T> extends _RoutePlaceholder {
   ///
   /// If this is true, then [isActive] is also true.
   bool get isCurrent {
-    if (_navigator == null) {
+    if (!_installed) {
       return false;
     }
     final _RouteEntry? currentRouteEntry = _navigator!._lastRouteEntryWhereOrNull(
@@ -596,7 +599,7 @@ abstract class Route<T> extends _RoutePlaceholder {
   /// If [isFirst] and [isCurrent] are both true then this is the only route on
   /// the navigator (and [isActive] will also be true).
   bool get isFirst {
-    if (_navigator == null) {
+    if (!_installed) {
       return false;
     }
     final _RouteEntry? currentRouteEntry = _navigator!._firstRouteEntryWhereOrNull(
@@ -611,7 +614,7 @@ abstract class Route<T> extends _RoutePlaceholder {
   /// Whether there is at least one active route underneath this route.
   @protected
   bool get hasActiveRouteBelow {
-    if (_navigator == null) {
+    if (!_installed) {
       return false;
     }
     for (final _RouteEntry entry in _navigator!._history) {
@@ -3213,7 +3216,7 @@ class _RouteEntry extends RouteTransitionRecord {
     );
     assert(navigator._debugLocked);
     assert(
-      route._navigator == null,
+      !route._installed,
       'The pushed route has already been used. When pushing a route, a new '
       'Route object must be provided.',
     );
@@ -3292,7 +3295,7 @@ class _RouteEntry extends RouteTransitionRecord {
   /// refuses to be popped.
   bool handlePop({required NavigatorState navigator, required Route<dynamic>? previousPresent}) {
     assert(navigator._debugLocked);
-    assert(route._navigator == navigator);
+    assert(route._isInstalledIn(navigator));
     currentState = _RouteLifecycle.popping;
     if (route._popCompleter.isCompleted) {
       // This is a page-based route popped through the Navigator.pop. The
@@ -3322,7 +3325,7 @@ class _RouteEntry extends RouteTransitionRecord {
     required Route<dynamic>? previousPresent,
   }) {
     assert(navigator._debugLocked);
-    if (route._navigator == navigator) {
+    if (route._isInstalledIn(navigator)) {
       currentState = _RouteLifecycle.removing;
     } else {
       // This route is still waiting to be added while a top-most push or pop
@@ -3336,7 +3339,7 @@ class _RouteEntry extends RouteTransitionRecord {
   }
 
   void didAdd({required NavigatorState navigator, required bool isNewFirst}) {
-    assert(route._navigator == null);
+    assert(!route._installed);
     route._navigator = navigator;
     route.install();
     assert(route.overlayEntries.isNotEmpty);
@@ -3436,7 +3439,7 @@ class _RouteEntry extends RouteTransitionRecord {
             if (!navigator._entryWaitingForSubTreeDisposal.remove(this)) {
               // This route must have been destroyed as a result of navigator
               // force dispose.
-              assert(route._navigator == null && !navigator.mounted);
+              assert(!route._installed && !navigator.mounted);
               return;
             }
             assert(currentState == _RouteLifecycle.disposing);
@@ -4484,9 +4487,12 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
           assert(entry.currentState == _RouteLifecycle.remove);
           continue;
         case _RouteLifecycle.remove:
-          if (!seenTopActiveRoute) {
+          // Routes that are not yet added (_installed == false) will exit as if
+          // they have never been on the navigator. They shouldn't announce
+          // their presence.
+          if (!seenTopActiveRoute && entry.route._installed) {
             if (poppedRoute != null) {
-              entry.route.didPopNext(poppedRoute);
+              entry.handleDidPopNext(poppedRoute);
             }
             poppedRoute = null;
           }
@@ -5049,7 +5055,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
       _debugLocked = true;
       return true;
     }());
-    assert(entry.route._navigator == null);
+    assert(!entry.route._installed);
     assert(entry.currentState == _RouteLifecycle.push);
     _history.add(entry);
     _flushHistoryUpdates();
@@ -5127,7 +5133,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
     Route<T> newRoute, {
     TO? result,
   }) {
-    assert(newRoute._navigator == null);
+    assert(!newRoute._installed);
     _pushReplacementEntry(
       _RouteEntry(newRoute, pageBased: false, initialState: _RouteLifecycle.pushReplace),
       result,
@@ -5181,7 +5187,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
       _debugLocked = true;
       return true;
     }());
-    assert(entry.route._navigator == null);
+    assert(!entry.route._installed);
     assert(_history.isNotEmpty);
     assert(
       _history.any(_RouteEntry.isPresentPredicate),
@@ -5228,7 +5234,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
   ///    restored during state restoration.
   @optionalTypeArgs
   Future<T?> pushAndRemoveUntil<T extends Object?>(Route<T> newRoute, RoutePredicate predicate) {
-    assert(newRoute._navigator == null);
+    assert(!newRoute._installed);
     assert(newRoute.overlayEntries.isEmpty);
     _pushEntryAndRemoveUntil(
       _RouteEntry(newRoute, pageBased: false, initialState: _RouteLifecycle.push),
@@ -5282,7 +5288,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
       _debugLocked = true;
       return true;
     }());
-    assert(entry.route._navigator == null);
+    assert(!entry.route._installed);
     assert(entry.route.overlayEntries.isEmpty);
     assert(entry.currentState == _RouteLifecycle.push);
     int index = _history.length - 1;
@@ -5315,7 +5321,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
   @optionalTypeArgs
   void replace<T extends Object?>({required Route<dynamic> oldRoute, required Route<T> newRoute}) {
     assert(!_debugLocked);
-    assert(oldRoute._navigator == this);
+    assert(oldRoute._isInstalledIn(this));
     _replaceEntry(
       _RouteEntry(newRoute, pageBased: false, initialState: _RouteLifecycle.replace),
       oldRoute,
@@ -5337,7 +5343,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
     required RestorableRouteBuilder<T> newRouteBuilder,
     Object? arguments,
   }) {
-    assert(oldRoute._navigator == this);
+    assert(oldRoute._isInstalledIn(this));
     assert(
       _debugIsStaticCallback(newRouteBuilder),
       'The provided routeBuilder must be a static function.',
@@ -5365,7 +5371,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
       return true;
     }());
     assert(entry.currentState == _RouteLifecycle.replace);
-    assert(entry.route._navigator == null);
+    assert(!entry.route._installed);
     final int index = _history.indexWhere(_RouteEntry.isRoutePredicate(oldRoute));
     assert(index >= 0, 'This Navigator does not contain the specified oldRoute.');
     assert(
@@ -5401,8 +5407,8 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
     required Route<dynamic> anchorRoute,
     required Route<T> newRoute,
   }) {
-    assert(newRoute._navigator == null);
-    assert(anchorRoute._navigator == this);
+    assert(!newRoute._installed);
+    assert(anchorRoute._isInstalledIn(this));
     _replaceEntryBelow(
       _RouteEntry(newRoute, pageBased: false, initialState: _RouteLifecycle.replace),
       anchorRoute,
@@ -5425,7 +5431,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
     required RestorableRouteBuilder<T> newRouteBuilder,
     Object? arguments,
   }) {
-    assert(anchorRoute._navigator == this);
+    assert(anchorRoute._isInstalledIn(this));
     assert(
       _debugIsStaticCallback(newRouteBuilder),
       'The provided routeBuilder must be a static function.',
@@ -5515,7 +5521,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
     if (lastEntry == null) {
       return false;
     }
-    assert(lastEntry.route._navigator == this);
+    assert(lastEntry.route._isInstalledIn(this));
 
     // TODO(justinmc): When the deprecated willPop method is removed, delete
     // this code and use only popDisposition, below.
@@ -5636,7 +5642,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
       _debugLocked = true;
       return true;
     }());
-    assert(route._navigator == this);
+    assert(route._isInstalledIn(this));
     final bool wasCurrent = route.isCurrent;
     final _RouteEntry entry = _history.firstWhere(_RouteEntry.isRoutePredicate(route));
     entry.complete(result, isReplaced: false, imperativeRemoval: true);
@@ -5661,7 +5667,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
       _debugLocked = true;
       return true;
     }());
-    assert(anchorRoute._navigator == this);
+    assert(anchorRoute._isInstalledIn(this));
     final int anchorIndex = _history.indexWhere(_RouteEntry.isRoutePredicate(anchorRoute));
     assert(anchorIndex >= 0, 'This Navigator does not contain the specified anchorRoute.');
     assert(
diff --git a/packages/flutter/test/widgets/navigator_test.dart b/packages/flutter/test/widgets/navigator_test.dart
index 067a81335a1..c4846c8204e 100644
--- a/packages/flutter/test/widgets/navigator_test.dart
+++ b/packages/flutter/test/widgets/navigator_test.dart
@@ -280,6 +280,7 @@ void main() {
     expect(tester.widget<Overlay>(find.byType(Overlay)).clipBehavior, Clip.none);
   });
 
+  // Regression test for https://github.com/flutter/flutter/issues/170250.
   testWidgets('Can remove page before they are added', (WidgetTester tester) async {
     final GlobalKey<NavigatorState> key = GlobalKey<NavigatorState>();
     Future<void> buildPages(List<Page<void>> pages) {
@@ -337,6 +338,52 @@ void main() {
     expect(tester.takeException(), isNull);
   });
 
+  // Regression test for https://github.com/flutter/flutter/issues/177322.
+  testWidgets('Can remove page before they are added - case 2', (WidgetTester tester) async {
+    final GlobalKey<NavigatorState> key = GlobalKey<NavigatorState>();
+    Future<void> buildPages(List<Page<void>> pages) {
+      return tester.pumpWidget(
+        MediaQuery(
+          data: MediaQueryData.fromView(tester.view),
+          child: Directionality(
+            textDirection: TextDirection.ltr,
+            child: Navigator(key: key, pages: pages, onDidRemovePage: (_) {}),
+          ),
+        ),
+      );
+    }
+
+    const MaterialPage<void> page = MaterialPage<void>(
+      key: ValueKey<String>('page'),
+      child: Text('page'),
+    );
+    const MaterialPage<void> page1 = MaterialPage<void>(
+      key: ValueKey<String>('page1'),
+      child: Text('page1'),
+    );
+    const MaterialPage<void> page2 = MaterialPage<void>(
+      key: ValueKey<String>('page2'),
+      child: Text('page2'),
+    );
+    const MaterialPage<void> page3 = MaterialPage<void>(
+      key: ValueKey<String>('page3'),
+      child: Text('page3'),
+    );
+    await buildPages(<Page<void>>[page]);
+
+    expect(find.text('page'), findsOneWidget);
+
+    await buildPages(<Page<void>>[page, page1, page2, page3]);
+
+    // In mid transition;
+    await tester.pump(const Duration(microseconds: 150));
+    // Cause page1 and page2 to be removed before they are added.
+    await buildPages(<Page<void>>[page]);
+    await tester.pumpAndSettle();
+    expect(find.text('page'), findsOneWidget);
+    expect(tester.takeException(), isNull);
+  });
+
   testWidgets('Zero transition page-based route correctly notifies observers when it is popped', (
     WidgetTester tester,
   ) async {